1. Field of the invention
The invention relates to an integrated circuit, particularly to a setting method for an integrated circuit.
2. Description of the Related Art
FIG. 1 shows the relationship of the open system interconnection (OSI) seven-layer network model with the physical layer and media access control (MAC) layer. IEEE 802.3 defines the data frame format of the MAC layer 110 and the electrical characteristics of the physical layer 120. The physical layer 120 has different layer structure according to the bit rate. On one hand, the physical layer 120 communicates with the MAC layer 110 via the media independent interface (MII) or gigabit media independent interface (GMII). On the other hand, the physical layer 120 communicates with the physical medium layer 130 via a media dependent interface (MDI).
Generally, a network driver program is operated for the MAC layer to access or write registers of the physical layer circuit via MDC (management data clock)/MDIO (management data input/output) as shown in FIG. 3. In order to comply with the IEEE 802.3 standard, each physical layer circuit has five configuration pins to set the address of the physical layer circuit. In other words, one MAC layer can communicate with each different physical layer circuit via each different address. Under the IEEE 802.3 standard, the MAC layer 110 issues the management frame format as shown in FIG. 2 where the value in the PHYAD field is the address of the physical layer circuit which the MAC layer 110 attempts to communicate with. If the address of a physical layer circuit equals the value in the PHYAD field in the management frame format, this physical layer circuit is to be communicated with the MAC layer 110. However, under the specification of the 5-bit PHYAD value of the IEEE 802.3 standard, the conventional physical layer circuit uses these five configuration pins to receive a 5-bit address setting value in order to comply with the IEEE 802.3 standard.